I've used TPO liners a couple times now, and honestly, they've held up pretty well. Definitely agree they're tougher against punctures—had a situation last year where I dropped some sharp-edged flagstone pieces right onto the liner (yeah, clumsy moment...), and it didn't even scratch. EPDM probably would've torn or at least gotten nicked.
Long-term though, I can't say for sure yet. My oldest TPO install is about 4 years old now, still looks solid with no noticeable deterioration or brittleness. EPDM liners I've had for 10+ years are still going strong too, but they do seem to soften or stretch a bit over time, especially in direct sun. TPO seems more rigid overall, which might help it keep shape better long-term.
One thing to watch out for: TPO can be trickier to fold neatly into corners because it's stiffer. Takes a bit more patience and planning during install. But if you're careful and take your time, it's manageable and worth the extra effort IMO.
Good points on TPO stiffness. I've noticed similar issues when inspecting installations—corners can get messy if the installer rushes it.
"EPDM liners I've had for 10+ years are still going strong too, but they do seem to soften or stretch a bit over time, especially in direct sun."
True, EPDM does stretch, but sometimes that flexibility helps it adapt better to minor settling or shifting underneath. Curious if anyone's seen how TPO handles ground movement or settling long-term? Haven't come across many older installations yet myself.
Good observations on EPDM flexibility—seen that myself a few times. On TPO, I've inspected a couple of 7-8 year old installs. Quick notes:
- Seems to hold shape pretty well, minimal stretching.
- Noticed minor stress lines at corners (probably rushed install).
- Haven't seen major ground shifting yet, but suspect TPO would struggle more than EPDM due to stiffness.
Still early days though...would love to revisit those sites in another 5 years and see how they're holding up.
"Noticed minor stress lines at corners (probably rushed install)."
Haha, been there. My TPO install's around 6 years old now—corners look like my first attempt at gift wrapping... holding up okay, but definitely not winning any beauty contests. Curious to see how it ages.
I feel you on the corners—my EPDM install is about 8 years old now, and the edges definitely have that "DIY weekend warrior" vibe. But honestly, the underlayment beneath it has been a lifesaver. Went with a mid-range synthetic option after tons of research (and spreadsheet comparisons, lol), and it's held up surprisingly well. No leaks or moisture issues yet...knock on wood. Curious if anyone else has noticed a big difference between budget and premium underlayments over time?
